Hi everybody and my apology for the long thread.
I have been working on my daughters 1993 940 regina with 194,000 miles,trying to solve a fuel consumption problem, noticed is only hapening at idle (in cold weather especially).
In warm weather i get 31-33 mpg highway and 24-26 city,in cold weather i get 14-16 same for highway and city.Here what i have done so far:
New sp.plugs,wires,dist.cap,rotor,fuel filter and air filter (old spark plugs looked fine).
New fuel pressure regulator (old one looked fine).
New knock sensor.
Cleaned breather system, throttle body,idle control valve,adjusted and tested throttle body switch.
Cleaned and lubricated the ignition coil,also swaped it for a known good one.
Tested ECT sensor at ECU pins warm and cold (readings were within specs).
Tested AIR and MAP sensor (readings were within specs),also swaped them for known good ones.
Tested Oxygen sensor (readings were within specs)also swaped another one.
Cleaned all body grounds,listened for all injectors thiking,checked engine oil and no gas is present.
Swaped the instrument cluster thinking for bad odometer reading,no change.
Car starts fine hot or cold so i concluded the cold start valve is fine,have another ECU to swap,last chance.
Hope did not forget anything,and would like to mention that i noticed the fuel consumption is hapening when the engine is idling (for example warming it in cold weather).
Thankyou for your time,and appreciate any help solving this problem.
Charles.